start with your 15 rep max
10sets once a week to near failure each set.
When you do a set with only 3reps, stop benching for the day.
Then Dips: 10sets, same progression but minimum 5reps.
Add 10lbs on both dips and bench every workout.
When you can’t do 5sets or more, add assist to keep up volume:
DB Shoulder Press and Skull Crushers 5sets with 15rep weight
Add 10lbs every workout here too
When you can get no more than 5reps on bench, do only 1 set and decrease Dips to only 1set as well. That way you can progress more on assist. add 2 backoff sets to bench with 20-50lbs less (something you can do for 5-8reps when tired) than topset and do those AFTER the assist work. Assist work will keep improving.
When you can no longer do 5reps on the bench topset, try a new max and done.
(credit to: George Leeman)